Convert iterator to list to list before looping through moments r ops…

… in insert (quantumlib#5820)
rht · May 1, 2023 · c8d30d6 · c8d30d6
1 parent ca46f04
commit c8d30d6
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/cirq-core/cirq/circuits/circuit.py b/cirq-core/cirq/circuits/circuit.py
@@ -2083,7 +2083,7 @@ def insert(
         """
         # limit index to 0..len(self._moments), also deal with indices smaller 0
         k = max(min(index if index >= 0 else len(self._moments) + index, len(self._moments)), 0)
-        for moment_or_op in ops.flatten_to_ops_or_moments(moment_or_operation_tree):
+        for moment_or_op in list(ops.flatten_to_ops_or_moments(moment_or_operation_tree)):
             if isinstance(moment_or_op, Moment):
                 self._moments.insert(k, moment_or_op)
                 k += 1

diff --git a/cirq-core/cirq/circuits/circuit_test.py b/cirq-core/cirq/circuits/circuit_test.py
@@ -187,6 +187,12 @@ def test_append_single():
     c.append([cirq.X(a)])
     assert c == cirq.Circuit([cirq.Moment([cirq.X(a)])])
 
+    c = cirq.Circuit(cirq.H(a))
+    c.append(c)
+    assert c == cirq.Circuit(
+        [cirq.Moment(cirq.H(cirq.NamedQubit('a'))), cirq.Moment(cirq.H(cirq.NamedQubit('a')))]
+    )
+
 
 def test_append_control_key():
     q0, q1, q2 = cirq.LineQubit.range(3)